Sequential electric switching system



July 29, 1947. F. R. JACKSON, JR

SEQUENTIAL ELECTRIC SWITCHING SYSTEM Filed June 20, 1945 Inventor:Frederick R. Jackson Jr,

Patented July 29, 1947 SEQUENTIAL ELECTRIC SWITCHING SYSTEM Frederick R.Jackson, Jr., Pittsiield, Mutt, asaignor to General Electric Company, acorporation of New York Application June 20, 1945, Serial No. 600,602

My invention relates to sequence control arrangements and particularlyto an arrangement for sequentially controlling two switches so that theyare alternately closed for a predetermined time interval with apredetermined time interval between successive switch closures.

One object of my invention is to provide an improved arrangement ofparts whereby the time interval each switch is closed and the timeinterval between successive switch closures may .be readily adjustedindependentlyof each other.

My invention will be better understood from the following descriptionwhen taken in connection with the accom anying drawing, the singlefigure of which diagrammatically illustrates an embodiment of myinvention in connection with an arrangement for alternately connectingtwo electric circuits to a third electric circuit, and the scope of myinvention will be pointed out in the appended claims,

Referring to the drawing, I and 2 represent two electric circuits whichare arranged to be connected to a third electric circuit I by theswitches 4 and I, respectively. In accordance with my invention, Iprovide a control arrangement for the switches 4 and I so that thecircuit I is alternately connected to and disconnected from the circuitsI and 2 including a time relay I which controls the length of time eachswitch is maintained in its closed position and a time relay 1 whichcontrols the length of time between successive switch closures. Asshown, the time relay I is arranged to be energized when either theswitch 4 or the switch I is closed, and the time relay I is arranged tobe energized when both oi. the switches 4 and I are open at the sametime. I is an auxiliary relay which, when deenergized, is arranged to beenergized to effect the closing of the switch 4 in response to the timerelay I completing its timing operation. I is another auxiliary relaywhich is arranged to be energized to eflect the opening oi! the switch 4in response to the time relay I completing its timing operation whilethe switch 4 is closed. The auxiliary relays I and I are arranged tocomplete locking circuits for themselves. The time relay I, when itcompletes its timing operation in response to the opening of the switch4, is arranged to eflect the closing of the switch I. and the time relayI, when it completes its timing operation in response to the closing ofthe switch I, is arranged to eflect the opening or the switch I and theopening or the locking circuits oi the auxiliary relays I and I so thatthe next completion of the timing relay 1 in response to the opening 01the switch I initiates 5 Claims. (Cl. -075) 2 another cycle of operationof the switches 4 and I. A control switch II is provided which, whenclosed, renders the sequence control arrangement operative.

The operation of the control arrangement is as follows: When the controlswitch I0 is closed, an energizing circuit is completed for the timerelay 1 through the contacts or the control switch III, the contacts I Iof the open switch 4 and the contacts I2 oi the open switch I. When thetime relay I completes its timing operation and closes its contacts II,an energizing circuit is completed for the auxiliary relay I through thecontacts of the control switch It) and the contacts II of the auxiliaryrelay I. The closing of the contacts II of the auxiliary relay Icompletes a locking circuit tor the winding of relay I through thecontacts o! the control switch II and the parallelconnected contacts IIand II of the time relay I and of the switch I, respectively. Theclosing of the contacts II of the auxiliary relay I completes anenergizing circuit for the operating winding of the switch 4 through thecontacts II of the auxiliary relay 9, the parallel-connected contacts IIand ll of the time relay I and oi! the switch I, respectively, thecontacts II of the auxiliary relay I and the contacts 01' the controlswitch III. The closing of the main contacts oi! the switch I connectsthe electric circuit I to the electric circuit I, and the opening of thecontacts IIoi the switch 4 interrupts the energizing circuit or the timerelay 1. The closing of the auxiliary contacts 20 of the switch 4'completes an energizing circuit for the time relay I through thecontacts of the control switch II. The opening of the contacts II of thetime relay 1 does not effect the deenergization of the windings of theauxiliary relay I and the switch 4 at this time because the circuits ofthese windings are now completed through the parallel-connected contactsII and I1 0! the time relay I and of the switch I, respectively, and thecontacts II of the auxiliary relay 8.

When the time relay I completes its timing operation and closes itscontacts 2I, an energizing circuit is completed for the auxiliary relay9 through the contacts ll of the switch I, the contacts II oi theauxiliary relay 8 and the contacts of the control switch II. The closingof the contacts 22 of the auxiliary relay 9 completes a shunt circuitaround the contacts 2L0! the time relay I so that a locking circuit iscompleted for the auxiliary relay 9 to maintain the relay energizedafter the time relay I subsequently opens its contacts 2i. The openingof the contacts II 01' the auxiliary relay I interrupts the heretoforedescribed energizing circuit for the operating winding of the switch 4so that the electric circuit I is disconnected from the electric circuit3. The openin of the contacts 20 of the switch I interrupts theenergizing circuit for the time relay I, and the closing of the contactsI l of the switch 4 re-establishes the heretofore described energizingcircuit for the time relay 1.

When the time relay 1 completes its timing operation and closes itscontacts it while both of the auxiliary relays 8 and 5 are energized, anenergizing circuit for the operating winding oi the switch 5 iscompleted through the contacts of the control switch l and the contacts23 01 the energized auxiliary relay 9. The closing or the main contactsof the switch connects the electric circuit 2 to the electric circuit 3.The closing of the auxiliary contacts 24 of the switch 5 completes alocking circuit for the operating winding of the switch 5 through thecontacts ll of the time relay ii, the contacts [5 of the energizedauxiliary relay 8 and the contacts of the control switch Ill. Theopening of the contacts [2 of the switch -5 interrupts the energizingcircuit or the time relay 1, and the closing of the contacts 25 0fthe'switch 5 completes an energizing circuit for the time relay 6through the contacts of the control switch ill.

When the time relay 6 completes its timing operation while the switch .5is closed, the opening of the contacts H5 or the relay 6 interrupts theheretofore described locking circuits {or the auxiliary relays 8 and 8and for the operating winding of the switch 5 so that the electriccircuit 2 is disconnected from the electric circuit 3. The opening ofthe auxiliary contacts 25 or the switch 5 interrupts the energizingcircuit for the time relay 8, and the closing of the auxiliary contacts(2 of the switch 5 re-establishes the energizing circuit for the timerelay 1 which, after being energized for a predetermined time, initiatesanother closing of the switch 4 in the manner heretofore described.

It will be observed that in the arrangement shown in the drawing thelength of time the switches 4 and '5 are closed may be adjusted byvarying the operating time of the time relay 6 and that the length oftime the two switches remain open may be adjusted by varying theoperating time of the time relay 1, and any adjustment in the operatingtime of either time relay in no way affects the operating time of theother.

While I have, in accordance with the patent statutes, shown anddescribed my invention as applied to a particular system and asembodying various devices diagrammatically indicated, changes andmodifications will be obvious to those skilled in the art, and Itherefore aim in the appended claims to cover all such changes andmodifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent in the UnitedStates is:

1. In combination, two switches, a timing device, means for effecting atiming operation of said timing device in response to both of saidswitches being simultaneously open, a second tim ing device, means forefl'ecting a timing operation of said second timing device in responseto either of said switches being closed, and means jointly controlled bysaid timing devices for effecting the alternate closing of said switchesin response to successive timing operations of said first mentionedtiming device and 01- effecting the alternate opening of said switchesin response 4 to successive timing operations or said second timingdevice.

2. In-combination, two switches, a timing device. means for eilecting atiming operation of said timing device in response to both of saidswitches being simultaneously open, a second timing device, means foreflecting a timing operation of said second timing device in response toeither of said switches being closed. means for effecting the closing oia predetermined one 0! said switches in response to said first mentionedtiming device completing its timing operation, means for eflecting theopening of said predetermined one of said switches in response to saidsecond timing device completing its timing operation while saidpredetermined one or said switches is closed, means for effecting theclosing or the other of said switches in response to said firstmentioned timing device completing its timing operation when said one ofsaid switches is opened by said second timing device, and means forefl'ecting the opening of said other or said switches in response tosaid second timing device completing its timing operation when saidother 01' said switches is closed.

3. In combination, two switches, a timing device, means ior effecting atiming operation of said timing device in response to both or saidswitches being simultaneously open, a second timing device, means foreffecting a timing operation of said second timing device in response toeither or said switches being closed, an auxiliary relay, means foreffecting the energization of and the completion of a locking circuitfor said auxiliary relay and th closing of a, predetermined one or saidswitches in response to said first mentioned timing device completingits timing operation while said auxiliary relay is deenergized, meansfor effecting the opening 01' said predetermined one of said switches inresponse to said second timing device completing its timing operationwhile said predetermined one of said switches is closed, means foreffecting the closing 01' the other of said switches in response to saidfirst mentioned timing device completing its timing operation when saidone of said switches is opened by said second timing device, and meansfor eflecting the opening or said other 0! said switches and of saidlocking circuit in response to said second timing device completing itstiming operation when said other of said switches is closed.

4. In combination, two switches, a timing device, means for effecting atiming operation or said timing device in response to both 01' saidswitches being simultaneously open, a second timing device, means foreflecting a timing operation or said second timing device in response toeither or said switches being closed, two auxiliary relays, means foreiiecting the energization of and the completion or a locking circuitfor one 01' said auxiliary relays and the closing oi a predetermined one01' said switches in response to one or said timing devices completingits timing operation while both of said auxiliary relays aredeenergized, means for eii'ecting the energization of and the completionof a locking circuit for the other or said auxiliary relays and theopening or said predetermined one of said switches in response to saidsecond timing device completing its timing operation while said one ofsaid auxiliary relays is energized, means for effecting the closing ofthe other or said switches in response to said one of said timingdevices completing its timing operation while both of said auxiliaryrelays are energized, and means for eii'ecting the opening of said otherof said switches and the opening of all of said locking circuits inresponse to said second timing device completing its timing operationwhile both of said auxiliary relays are energized.

5. In combination, two switches, a time relay, means controlled by saidswitches for efiectlng a timing operation of said relay when both ofsaid switches are open, a second time relay, means controlled by saidswitches for eflecting a timing operation of said second time relay wheneither of said switches is closed, an auxiliary relay, a secondaryauxiliary relay, means controlled by said first mentioned time relay andsaid second auxiliary relay for effecting the energization of said firstmentioned auxiliary relay in response to said first mentioned time relaycompleting its timing operation when said second auxiliary relay isdeenergized, a locking circuit for said first mentioned auxiliary relay,means controlled by said auxiliary relays for eflecting the closing ofone of said switches when said first mentioned auxiliary relay isenergized and said second auxiliary relay is deenergized, meanscontrolled by said second time relay and said auxiliary relays foreffecting the energization of said second auxiliary relay in response tosaid second time relay completing its timing operation when 6 said firstmentioned auxiliary relay is energized and said second auxiliary relayis deenergized, a locking circuit for said second auxiliary relay, meansresponsive to the energization of said second auxiliary relay foreffecting the opening of said one of said switches, means controlled bysaid second auxiliary relay and said first mentioned time relay foreffecting the closing of said other switch in response to said firstmentioned time relay completing its timing operation while said secondauxiliary relay is energized, and means controlled by said second timerelay for efiecting the opening of said other switch and said lockingcircuits in response to said second time relay completing its timingoperation when said other switch is closed.

FREDERICK R. JACKSON, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,140,601 Serriere Dec. 20, 19382,370,727 Holden Mar. 6, 1945

